The present invention generally relates to a tool used for working a tire from the rim of a wheel, and more particularly, to such a tool having a first working end that is used to demount a first tire bead from a wheel rim and a second working end used to demount a second tire bead from the wheel rim.
From time to time, pneumatic tires require repair or replacement. To service such tires, the tire must be removed from the wheel rim. A variety of tools have been developed and utilized to facilitate the working of tires. Such tools typically comprise an elongate bar having a handle and a working end adapted to be inserted between the tire bead and wheel rim. The working end of the tool frequently has a flattened or tapered portion to facilitate insertion of the working end between the tire bead and the wheel rim. The working ends of known tools are configured, in profile, as either straight, curved, or angled.
To utilize the implement, the tool working portion is inserted manually between the bead of the tire and its associate wheel rim. Thereafter, the user applies pressure on the handle and moves a portion of the working end into contact with the wheel rim, whereby establishing the wheel rim as a fulcrum and making a lever of the tool. Pressure upon the handle causes the tool working end to engage and move a segment of the tire bead inward and allows the tire bead to be stretched over the rim by moving the tool around the periphery of the tire. In more recent years, machines have been developed which rotate the tire in conjunction with the use of the tool to alleviate the need for moving the tool.
While the prior art is replete with working tools, the basic design has not changed significantly over the years. Known designs, while working well to an extent, have proven less than satisfactory in providing an optimally functional tire working implement. Some known devices remove tubeless truck tires by using separate tools for each tire bead. A first working tool is used to stretch the first bead of the tire over the rim. Then, a second working tool is inserted between the second tire bead and the wheel rim and leverages the second bead over the rim to complete removal of the tire. Use of separate implements, however, increases cost and complicates the procedure.
To aid in the removal process, some designs incorporate a projection that extends from the bottom of the flattened portion to create additional leverage when engaged with the wheel rim. Projections, however, carry a disadvantage in that they contact the wheel rim at a single point. Other devices use rollers as the pivot point between the tool and wheel rim. Rollers are undesirable in use because they are prone to movement during the working process and such movement can reduce the mechanical advantage provided by the tool. Still other designs use a bend in the mounting tool working end to create a pivot point. A bend is advantageous to an extent but, as with a projection, it provides only a single point of contact with the wheel rim. With only one point of contact, the tool is prone to rocking or slipping on the rim during the tire removal procedure. Rocking or slipping can dislodge the working tool and require the user to begin the working process anew. At best, rocking or slipping necessarily causes the user to exert additional effort and concentration to maintain the working tool in its proper position.
An additional disadvantage attends the use of conventional working tools. During the working process, the first tire bead is typically removed first by laying the tire flat on the ground or other supporting surface and inserting the working tool between the first bead and the rim. The tool is then used as a lever to work the first bead over the rim. After the first bead is removed from its position on the rim, the tire is then lifted to enable insertion of the second bead working tool between the second bead and the rim. Thereafter, the tire is dropped and acts under force of gravity to free the second bead. As can be appreciated, this repeated manual elevation of tires requires a significant amount of exertion by the user and may be impractical for less powerful users of the tool.
Other known second working tool designs comprise a straight tool having a tip that angles downwardly from the longitudinal plane of the tool. While a downward bend creates a more efficient lever, the downward turned tip, however, makes insertion difficult and requires inserting the tip at a sideways angle to the bead. A user will typically insert the tip between the tire bead and the wheel rim, leading with a corner of the tip, and gradually working the remainder of the tip underneath. This process is time consuming, and requires significant effort. A further disadvantage is that, once inserted, the straight portion of the tool presses against the sidewall and tread of the tire in the course of leveraging the tire bead. Since only the bead must be raised outside of the rim, the force exerted against the sidewall and tread does not directly contribute toward a removal of the bead. The flexible sidewall, in fact, absorbs a significant amount of force through deformation before useful force is transmitted to the bead. Thus, more force is required to operate such tools and represents, again, an ergonomic disadvantage to the user. Moreover, by impinging against and applying a significant leverage force against the sidewall of the tire, conventional tools can cause damage to the tire sidewall and tread areas.
As a consequence, there is a need for a working tool that reduces the likelihood of rocking or sliding of the tool during tire removal. There is a further need for a working tool that is more easily inserted between the bead and the rim. There is a further need for a working tool that does not rest against the sidewall while leveraging the second tire bead from the wheel rim. There is a further need for a working tool that does not require that the tire be lifted by the user in order to removes the second tire bead from the wheel rim.
It is, therefore, an object of the present invention to provide a working tool that reduces the likelihood that the tool working end will rock or move during the removal of the tire.
It is a further object of the present invention to provide a working tool that creates more than one point of contact between the working tool and the rim.
It is a further object of the present invention to provide a working tool having a heel portion and ball portion that provide simultaneous contact with the wheel rim during tire removal.
It is a further object of the present invention to provide a working tool having a configuration that establishes and maintains positive contact with the rim to reduce the likelihood of lateral rocking of the tool.
It is another object of the present invention to provide a working tool having a working end capable of removing the second tire bead without necessitating an elevation of the tire.
It is a further object of the present invention to provide a working tool having a working end having a reach sufficient to extend beyond the previously removed first bead to demount the second bead from the rim.
It is a further object of the present invention to provide a second bead working tool that is more easily inserted between the second bead and the wheel rim.
It is a further object of the present invention to provide a working tool having a tapered tip that is more easily inserted between a tire bead and the wheel rim.
It is a further object of the present invention to provide a second bead working tool that does not impinge against the sidewall during tire removal.
It is a further object of the present invention to provide a second bead working tool having a working end that is offset from the handle.
In view of these objects the present invention generally provides a tire demounting tool comprising a handle and first and second working ends extending radially outward from opposite handle ends. The first working end includes a heel portion and a lever arm radially extending outward therefrom. The lever arm comprises a rearwardly directed first segment and a forwardly directed second segment connecting to the first segment at a bend portion and defining with the first segment a forward opening crook. A tip portion connects to the second arm segment and is positioned at a remote end of the lever arm. A forwardly projecting ball portion is carried by the lever arm and is positioned proximate the bend portion. A pair of spaced apart ridges are formed to extend along a portion of the lever arm surface defining the crook and provides added stability against a wheel rim during deployment of the tool. The lever arm narrows and tapers across the tip portion to a leading edge to facilitate an easy insertion of the tip between a first tire bead and a wheel rim. The second working end of the tool, in a first embodiment, is configured similarly. The second lever arm comprises a rearwardly extending first segment and a second segment connecting to the first segment at a bend portion. The first and second segments define a forward facing crook at least partially defined by spaced apart ridge projections. The second lever arm segment is elongated to reach across the first tire bead and reach the second bead, and terminates at a tapered tip.
The above and other objectives are achieved by a preferred embodiment that is described in detail below and illustrated in the accompanying drawings.